Researchers find that patients with obesity and metabolic syndrome saw mental decline more than 22 percent faster than those who did not have these symptoms.

A new French study has found a link between obesity in middle-age and mental decline.

The study, which was published recently in the journal Neurology, was conducted by researchers at the Center for Research in Epidemiology & Population Health at INSERM, in Paris. The study evaluated participants who also had at least three of the four signs of metabolic syndrome: obesity, high blood pressure, high blood sugar, or high cholesterol. Metabolic syndrome is defined as a cluster of these four symptoms that is an early indicator of heart disease and diabetes.

The study's participants were drawn from the long-running Whitehall II study, which began in 1985 and follows British civil servants from middle-age onward. Researchers conducted a decade of research on more than 6,400 of these participants who were aged 39 to 63. Over the course of the ten-year study period, participants took tests on memory, reasoning and overall mental function at three intervals, while researchers continually tracked health data, including weight.

The greatest mental decline was seen in patients who were obese and also had metabolic syndrome. These patients had a loss of mental function that was 22.5 percent faster than those who weren't obese and didn't suffer from the syndrome. Still, even patients who did not have metabolic syndrome but were obese also saw mental decline occur more rapidly than participants who were not obese.

Bottom line: Take steps to protect your physical health and you will be protecting your mental health as well.